I can login and files and admin pages works smoothly, but users page opens but just shows rolling and not loading any users.
ownCloud 9.1.0 (stable)
Mariadb
CentOS 7
As described in your issue try the todays released oC 9.1.1 before reporting issues in 9.1.0 which might be already fixed there.
If you have updated to 9.1.1 and the issue is still there create a new thread an make sure that you're filling out the prefilled template shown when creating a new thread.